I looked at the API documentation and it was not immediately apparent to me. Is it available via partner access?
Also, the default rolling average for sentiment seems to be 7 days. Is there an option to change this. One obvious way of doing this is parsing the firehose and some partners probably do that. I don't care for all that data or parsing it, in the unlikely scenario where I can get access to that.
The Sentiment data is only available to partners that license our API. Please touch base with us and let us know what you would like to do and about your paid product:
http://stocktwits.com/developers/contact
There currently is no option to change the rolling average, we have plans to add different time frames, as we agree this would be helpful.